Putting fences around medical marijuana use

Even as a proposal to legalize medical marijuana emerges in Maryland, a backlash over the burgeoning industry has developed in other states - and is likely to influence legislation here.

Last week, the Los Angeles City Council tried to rein in the growth of marijuana dispensaries, limiting the number to 70 and imposing tight restrictions on where and how they can operate. And in Colorado, towns are trying to shutter some of the hundreds of dispensaries that have popped up.